| Name | Location | County | Country | Power source | Type | Function | River |
| Artificial Slate Works, Woodford Bridge | Woodford Bridge | Essex | United Kingdom | Water | Watermill | Slate mill | Roding |
| Felin Sarn, Clwt-y-bont | Clwt-y-bont, Llanddeiniolen | Caernarfonshire | United Kingdom | Water | Watermill | Slate mill | Marchlyn-bach |
| Graig Ddu Slate Works, Blaenau Ffestiniog | Blaenau Ffestiniog, Ffestiniog | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | |
| Hafodlas Slate Quarry Mills, Betws-y-Coed | Betws-y-Coed | Caernarfonshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Tributary to Llugwy |
| Pant-yr-ynn Slate Mill, Bethania, Blaenau Ffestiniog | Bethania, Blaenau Ffestiniog | Merionethshire | United Kingdom | Water | Watermill | Slate mill, Woollen mill | Afon Du-bach |
| Slate mill (1), Bwlch Cwmllan Slate Quarry | Bwlch Cwmllan, Betws Garmon | Caernarfonshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Tributary to Cwm Llan |
| Slate mill (2), Bwlch Cwmllan Slate Quarry | Bwlch Cwmllan, Betws Garmon | Caernarfonshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Tributary to Cwm Llan |
| Slate mill, Aberllefenni | Aberllefenni, Corris | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Dulas |
| Slate mill, Dolgarth Slate Quarry | Dolbenmaen | Caernarfonshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Ceunant Dolgerth |
| Slate mill, Drum Slate Quarry, Blaenau Ffestiniog | Blaenau Ffestiniog, Ffestiniog | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Gamallt |
| Slate mill, Minllyn Quarry, Minllyn | Minllyn, Mawddwy | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | Nant Minllyn |
| Slate mill, Rhyd-y-sarn | Llan Ffestiniog, Ffestiniog | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill, Tannery | Teigl |
| Slate mill, Wrysgan Quarry, Blaenau Ffestiniog | Wrysgan Quarry, Blaenau Ffestiniog | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | |
| Slate mills, Croesor Quarry, Croesor | Croesor Quarry, Croesor | Merionethshire | United Kingdom | Water | Watermill | Quarry mill/wheel, Slate mill | |
| Ynys-y-pandy Slate Mill, Cwmystradllyn | Cwmystradllyn | Caernarfonshire | United Kingdom | Water | Watermill | Slate mill | Afon Cwmystradllyn |